THE CULTURE OF ANAEROBIC BACTERIA. 311 



employed and no apparatus is necessary. The methods re- 

 ferred to are: stab culture in deep layers of gelatin or agar, 

 and cultivation in glucose litmus gelatin. 



The various forms of apparatus indicated above and 

 described fully in most of the text-books, are far from 

 being- satisfactory. The use of special tubes or of special 

 plates, where a large number are to be used, is a matter of 

 considerable expense. The treatment of each tube by 

 itself and the subsequent sealing- involves a waste of time, 

 and is not altogether free from danger. At least one death 

 is recorded as the result of endeavoring to seal a hydrogen 

 culture of the tetanus bacillus. It is obviously desirable 

 to make use of the ordinary test-tubes and ordinary Petri 

 dishes. This can be done by means of the special ap- 

 paratus 1 shown in Fig. 51-53. During the past six years 

 this apparatus has been in constant use in this laboratory, 

 and the fact that frequently several hundred cultures are 

 made by the students at one time will indicate its practical 

 usefulness. 



The bottle shown in Fig. 51 is intended for tube culture. 

 It is made in two sizes, for large and for small tubes. The 

 small bottle has an internal diameter of 8 cm. , and the in- 

 side height to the neck should be 16 cm. The large bottle 

 has a corresponding diameter of 10 cm. and a depth of 20 

 cm. It is provided with a hollow stopper which should be 

 not less than 4 cm. in diameter. There are openings in the 

 glass stopper corresponding to the two tubes in the neck of 

 the bottle. One of these openings has a glass tube attached 

 which extends down to within a short distance of the bot- 

 tom. After the gas has been passed for some time, the 

 stopper is turned through an angle of 90, thus effectually 

 sealing the bottle. 



Ordinary test-tubes containing glucose bouillon, gela- 

 tin, agar or potato are inoculated in the usual manner. The 

 projecting part of the cotton plug is cut off close to the 



1 Centralblatt fur Bakteriologie U, p. 581, 1893; 16, p. 566, 1894. 



